Voicemail not working

I have 3CX v7.0 on a XP pro PC. At some stage over the last few weeks voicemail has failed. It certainly worked when using v6.x but now I have a problem. Calls are forwarded to voicemail when the forwarding rules are met and the caller is prompted to leave a message but when you try to retrieve voicemail there are no messages. Additionally emails are not being sent to alert suscribers of voicemail

I tried to stop the voicemail service within the 3CX console and got this error message: